Download MAX698/MAX699 Low-Cost, Power-On Reset and Watchdog Controllers General Description

MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
General Description
The MAX698/MAX699 monitor the +5V supply in microprocessor (µP) and digital systems. They supply a
RESET pulse of at least 140ms duration on power-up,
power-down, and during low-voltage brownout conditions. Circuit reliability is increased at reduced cost by
eliminating all external components and adjustments.
The MAX699 includes all features of the MAX698, but
also provides a watchdog input to monitor microprocessor activity. The RESET output goes low if the watchdog
input (WDI) is not toggled within 1 second. The watchdog feature can be disabled by leaving WDI open.
Both parts are supplied in 8-lead PDIP and 16-lead
0.3in wide small outline (SO) packages and are specified from 0°C to +70°C for C grade devices and -40°C
to +85°C for E devices. The SO versions, with more
pins than the 8-lead PDIP, have additional outputs not
available in DIP packages. These are RESET (without
inversion) and watchdog output (WDO).
Applications
Features
o Precision Voltage Monitor
o Power-OK/Reset Time Delay
o Watchdog Timer
o Minimum Component Count
Ordering Information
PART*
MAX698CPA
MAX698CWE
TEMP RANGE
PIN-PACKAGE
0°C to +70°C
8 PDIP
0°C to +70°C
16 Wide SO
MAX698EPA
-40°C to +85°C
8 PDIP
MAX698EWE
-40°C to +85°C
16 Wide SO
MAX699CPA
0°C to +70°C
8 PDIP
MAX699CWE
0°C to +70°C
16 Wide SO
MAX699EPA
-40°C to +85°C
8 PDIP
MAX699EWE
-40°C to +85°C
16 Wide SO
Computers
*Devices are available in both leaded and lead(Pb)-free pack-
Controllers
aging. Specify lead free by adding the + symbol at the end of
the part number when ordering.
Intelligent Instruments
Automotive Systems
Pin Configuration
Critical µP Power Monitoring
TOP VIEW
Typical Operating Circuit
+5V
+
VCC
1
VCC
2
8
GND
7
RESET
MAX698
MAX699*
GND
3
6
N.C. (WDI)*
GND
4
5
N.C.
+5V
DIP
1
2
VCC
GND
RESET
VCC
8
7
MAX698
6
3
GND
N.C.
GND
N.C.
5
4
TO µP
RESET
INPUT
GND
1
16
RESET
VCC
2
15
RESET
VCC
3
14
N.C. (WDO)*
MAX698
MAX699*
GND
4
13
N.C.
N.C.
5
12
N.C.
N.C.
6
11
N.C. (WDI)*
N.C.
7
10
N.C.
N.C.
8
9
GND
* PIN LABELS IN ( ) ARE FOR MAX699 ONLY
SO
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-2349; Rev 4; 5/13
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
ABSOLUTE MAXIMUM RATINGS
VCC ........................................................................-0.3V to +6.0V
Input Voltage (with respect to GND)
WDI, WDO, RESET, RESET ..…………………………-0.3V to VCC
Operating Temperature Range
C Suffix………………………………………………0°C to +70°C
E Suffix ......……………………………………….-40°C to +85°C
Rate of Rise, VCC .................………………………………100V/µs
Power Dissipation (TA = +70°C)
8-Pin PDIP (derated 5mW/°C above +70°C).....………400mW
16-Pin SO (derated 7mW/°C above +70°C) ................600mW
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +5V, TA = +25°C, unless otherwise noted.)
PARAMETER
Operating Voltage Range
MIN
3.0
TYP
TA = full
CONDITIONS
MAX
5.5
UNITS
V
5
mA
Power-Up Reset Deassertion
TA = full
4.50
4.65
4.75
Power-Up Reset Assertion
TA = full
4.4
Supply Current
Hysteresis
40
Reset Output Pulse Width
RESET OUTPUT (Open Drain)
140
Output low
ISINK = 1.6mA, VCC = 4.4V
Output high
ISOURCE = 1µA, VCC = 5V
RESET OUTPUT (SO Package
Only)
Output low
ISINK = 1.6mA, VCC = 5V
Output high
ISOURCE = 1µA, VCC = 4.4V
WDO Output (MAX699 SO
Package Only)
Output low
ISINK = 1.6mA, VCC = 5V
Output high
ISOURCE = 1µA, VCC = 4.4V
3.5
0.4
3.5
0.4
3.5
1.00
MAX699 Minimum WDI Input
Pulse Width
200
MAX699 WDI Input Threshold
MAX699 WDI Input Current
2
VCC = +5V
2.25
0.8
20
-50
ms
V
V
V
s
ns
3.8
WDI = VCC
WDI = 0V
1.6
Locic-low
Logic-high
mV
500
0.4
MAX699 Watchdog Timeout
Period
V
V
-15
50
V
µA
Maxim Integrated
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
Pin Description
PIN
NAME
FUNCTION
SO
PDIP
1, 4, 9
3, 4, 8
GND
Chip Power Ground
2, 3
1, 2
VCC
+5V Sense Input and MAX698/MAX699 Chip Power
5–8, 10–14
5, 6
N.C.
No Connection
11
6
WDI (MAX699 Only)
(MAX699 Only.) A three-level input. If WDI remains high or low for
more than the watchdog timeout period, RESET pulses low (WDO
also goes low on the MAX699 SO package). If WDI is unconnected,
the watchdog circuit is disabled.
(MAX699 Only.) Goes low when WDI remains high or low for more
than the watchdog timeout period. WDO is set high at the next WDI
transition. If WDI is unconnected or at midsupply, WDO remains high.
WDO also remains high when VCC falls below 4.4V.
14
—
WDO (MAX699 Only)
15
7
RESET
Goes low when VCC falls below internally set threshold (see the
Electrical Characteristics table).
16
—
RESET
Goes high when VCC falls below internally set threshold.
WDI*
WATCHDOG
TIMER
WDO*
RESET
TIMER
RESET
VCC
RESET*
VCC
POWER-ON
RESET
MAX698
MAX699
4.65V
GND
*WDI ON MAX699 ONLY
RESET ON SO PACKAGE ONLY
WDO ON SO MAX699 ONLY
Figure 1. Block Diagram
Maxim Integrated
3
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
Package Information
Chip Topography
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PACKAGE
CODE
OUTLINE NO.
8 PDIP
P8-2
21-0043
—
21-0042
90-0107
16 Wide SO
4
LAND
PATTERN NO.
PACKAGE
TYPE
W16-1
Maxim Integrated
MAX698/MAX699
Low-Cost, Power-On Reset
and Watchdog Controllers
Revision History
REVISION
NUMBER
REVISION
DATE
4
5/13
DESCRIPTION
Corrected WDI SO pin number in Pin Description
PAGES
CHANGED
3
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent
licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and
max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
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